Antagonistic yeast and trehalose-enriched gelatin film: A bioactive antifungal packaging film for cherry tomato preservation

Abstract

To extend the shelf-life of cherry tomatoes infected with Botrytis cinerea, this study analyzed the effect of Pichia membranifaciens (PM) on a composite film of gelatin (Gel) and trehalose (Tre), and explored the effect of different concentrations of trehalose on the yeast in the bioactive film and its control effect on cherry tomatoes. Scanning electron microscopy showed that Tre/Gel-based film can be applied as effective carriers to protect the cellular integrity of PM. Fourier-transform infrared spectroscopy, thermogravimetric analysis, and tests of mechanical properties showed that there was interaction between PM and the Tre/Gel base film, which maintained the thermal stability of the base film. The addition of PM reduced the water vapor permeability, hygroscopicity, and moisture content of the Tre/Gel base film, effectively extending the active film's storage time. This study also explored the growth curve of PM and found that 15% trehalose was effective in maintaining PM activity and could result in a 30-day survival rate of 62% for PM in Tre/Gel films, with 72.41% inhibition of B. cinerea. Finally, the PM/Tre/Gel film significantly reduced the incidence of decay in cherry tomatoes and improved the storage quality and fungal resistance of the fruit. Thus, PM/Tre/Gel films may be applied as a new antifungal packaging material for the preservation of fresh fruit.